The molecular basis for the cariogenic properties of Streptococcus mutans will be investigated. Glucosyltransferase fractions synthesizing soluble and insoluble glucans will be purified to homogeneity and utilized to investigate the mechanism of adherent glucan formation. The interaction of these enzymes with phospholipids will be examined in order to assess the role of such interactions in the secretion and cell surface binding of the enzymes. It will also be of interest to investigate the role of enzyme-lipoteichoic acid complex formation on cell binding. Spheroplasts of S. mutans will also be prepared in order to investigate the synthesis and secretion of glucosyltransferases. Membrane fractions isolated from broken spheroplasts will also be utilized to examine the passage of the enzymes through this boundary and also to assess the role of intracellular invertase in the transport of sucrose.